"Cracking" into the debate about laying hen housing.

Livestock production systems have faced social pressures related to animal welfare; the laying hen industry also has faced changes in governing regulations/policies. This study employs experimental data to evaluate 3 confinement-housing systems: standard cages with no perches, cages with standard perches, and cages with cooled perches. Based on the cost-benefit analysis conducted of revenue less feed costs, operators are expected to have revenue, after covering feed costs, which could contribute to installation and maintenance of standard and/or cooled perches. Thus, egg producers may be able to use caged housing that incorporates perches profitably, depending on the final costs of such a system.

Yield and quality grade outcomes as affected by molecular breeding values for commercial beef cattle.

Although genetic tests for many economically important beef cattle traits are commercially available, additional information is needed to help the industry better understand how the results from these tests translate into phenotypic outcomes. This information has important implications for marker-assisted management. The objective of this research was to determine the relationship between molecular breeding values (MBV) characterizing yield grade and marbling and distributions of phenotypic outcomes for yield grade and quality grade. Using data collected from commercially-fed cattle, mixed-model regression equations were estimated for yield grade and quality grade outcomes for both the full sample of commercial cattle (n= 8,995) and a subsample of black-hided steers (n = 4,790). Significant yield grade (P < 0.01) and marbling (P < 0.01) MBV effects were found. However, the yield grade MBV held up better at predicting phenotypic outcomes than the marbling MBV. Estimated conditional probability mass functions of yield and quality grade outcomes for the general population and black-hided steers were similar. Since distributions for black-hided steers were expected to be more applicable from a management perspective, we focused our analysis on these animals. For example, black-hided steers with "low" genetic potential for yield grade and marbling had about a 29% chance of achieving the base price or better on a price grid (yield grade 3 or lower and quality grade Low Choice or better). Increasing genetic potential for marbling increased the likelihood of achieving this same outcome. However, increasing genetic potential for yield grade was unlikely to increase overall carcass quality given its large deleterious effect on quality grade outcomes. Instead, simultaneous improvements in genetic potential for yield grade and marbling offered much more reliable improvements in overall carcass quality. For example, an animal with "moderate" genetic potential for both yield grade and marbling had a 46% chance of achieving the base price or better on a price grid, and an animal with the maximum observed MBV for these traits had a 66% chance of achieving this same outcome. Although the yield grade MBV held up better at predicting phenotypic outcomes, shifts in the distributions of yield grade and quality grade suggested that these increases were largely determined by the marbling MBV.

Hypothalamic expression of human growth hormone induces post-pubertal hypergonadotrophism in male transgenic growth retarded rats.

Growth hormone (GH) is known to regulate peripheral components of the hypothalamo-pituitary gonadal (HPG) axis, but it remains unclear whether GH exerts a significant influence on the activity of the hypothalamo-pituitary components of the HPG axis. In this study, we investigated the development of HPG axis function in the male transgenic growth retarded (Tgr) rat, a model of moderate systemic GH deficiency caused by hypothalamic expression of human (h)GH. Impaired postnatal somatotroph expansion and moderate GH deficiency in male Tgr rats were accompanied by a two- to three-fold increase in pituitary gonadotrophin content, but without a significant change in the pituitary gonadotroph population. A three- to nine-fold elevation in basal circulating luteinising hormone concentration was seen in postpubertal Tgr rats, with a smaller increase in follicle-stimulating hormone. Despite this hypergonadotrophism, there was no corresponding increase in steroidogenic (circulating testosterone and seminal vesicle weights) or gametogenic (spermatozoa counts in seminiferous tubules) activity in the postpubertal Tgr testis. Following puberty, the plasma leptin concentration also became progressively elevated in Tgr males. Circulating gonadotrophin and leptin levels were normalised in Tgr rats by peripheral physiological replacement of rat GH, but plasma testosterone concentration was unaffected. These results confirm that hGH exerts a positive influence on the central control of gonadotrophin secretion in the Tgr rat, but the absence of a corresponding elevation in the steroidogenic or gametogenic function of the Tgr testis implies that the peripheral GH/insulin-like growth factor I axis may also exert a permissive influence on testicular function. The relative contribution of somatogenic and lactogenic mechanisms and the potential influence of elevated leptin and decreased sensitivity to androgen feedback to the development of postpubertal hypergonadotrophism in Tgr males remain to be determined.

Comparative analysis of the effects of ghrelin and unacylated ghrelin on luteinizing hormone secretion in male rats.

Ghrelin, the endogenous ligand of GH secretagogue receptor type 1a, has emerged as pleiotropic modulator of diverse biological functions, including energy homeostasis and, recently, reproduction. Although inhibitory actions of ghrelin on LH secretion and puberty onset have been reported previously, the receptor mechanisms mediating these actions, and the potential gonadotropic effects of the unacylated isoform of ghrelin (UAG), remain unclear. In this work, the effects of single and repeated administration of ghrelin or UAG on LH secretion were compared in pubertal and adult male rats. In addition, the effects of ghrelin were assessed in models of transient or persistent hypergonadotropism. Daily injection of ghrelin or UAG throughout puberty similarly decreased LH levels and partially delayed balanopreputial separation. Likewise, chronic infusion of ghrelin or UAG to adult males resulted in significant decreases in circulating LH and FSH concentrations. Moreover, acute injection of ghrelin induced a transient reduction in LH levels in freely moving males, an effect that was fully mimicked by administration of UAG. Yet in contrast to ghrelin, UAG failed to modify GH secretion. Finally, injection of ghrelin moderately, but significantly, reduced the duration of LH secretory responses to the potent gonadotropin secretagogue kisspeptin-10, whereas ghrelin infusion in a model of chronic elevation of serum gonadotropin levels (the transgenic growth retarded male rat) evoked a significant reduction of LH concentrations. Altogether our present results further substantiate the inhibitory effect of ghrelin on basal and stimulated LH secretion in a wide array of experimental conditions. Moreover, our data are the first to demonstrate the ability of UAG, originally considered an inert form of the molecule, to mimic the actions of acylated ghrelin on LH release. These observations reinforce the contention that ghrelin, as putative signal for energy insufficiency, may operate as negative modifier of male puberty and LH secretion, an effect that might be, at least partially, conducted through a GH secretagogue receptor type 1a-independent mechanism.

Neuroanatomic and neuropsychological outcome in school-age children with achondroplasia.

We previously reported on cognitive and respiratory factors in a series of infants with achondroplasia (ACH). We now present the results of neuropsychological evaluation and magnetic resonance imaging in 16 school-age children with ACH, 7 of whom had been included as infants in our previous report. We examined the neuroanatomic and cognitive status of this sample, as well as the predictive stability of the prior infant assessment. Seventeen normally developing children of average stature and 21 preterm children with arrested (compensated, unshunted) hydrocephalus constituted the comparison groups. Brain volumes of children with ACH were significantly larger than those of the comparison groups. In addition, children with ACH exhibited kinking of the medulla and neuroanatomic abnormalities consistent with arrested hydrocephalus, including enlarged ventricles and hypoplasia of the corpus callosum. Cognitive abilities at school age were average, although mild deficits were seen on visual-spatial tasks, similar to those obtained by the hydrocephalic comparison group. Only gross motor coordination deficits distinguished the ACH group from the hydrocephalic controls. Infant assessment overestimated later school-age IQ scores in those infants with ACH who scored above average. These findings point to generally preserved cognitive skills in selected children with ACH at early school age, although children with ACH should be evaluated individually as they are at risk for cognitive, academic, and motor deficits.

Growth hormone deficiency associated in the 18q deletion syndrome.

The 18q- syndrome is one of the commonest deletion syndromes. Clinical characteristics are variable but may include: hypotonia, tapered digits, "carp-like" mouth, mental retardation, and hearing impairment. Growth failure (GF; both weight and height < 3%) was reported in 80% of affected individuals. We evaluated growth hormone (GH) sufficiency in 5 18q- syndrome patients, 3 of whom had growth failure (< 3% weight and height); the remaining 2 had normal growth parameters. Laboratory evaluation of growth included measurement of IGF-1, IGFBP-3, bone ages and GH response to pituitary provocative agents. Three patients failed to produced adequate GH following stimulation testing. Of 3 patients with inadequate GH production, 1 had normal growth (above 3%). Only 1 of 5 patients had normal GH production and normal growth parameters. Our findings to date suggest that GH deficiency is common in individuals with the 18q- syndrome. The pathogenesis of this finding is unknown. We postulate that a gene(s) on 18q is involved in GH production.

Characteristics of adolescent girls with depressive symptoms in a so-called "normal' sample.

OBJECTIVE: Forty-four percent of adolescent girls who had been screened for absence of psychiatric disorder reported depressive symptoms on a structured interview. Girls reporting symptoms were assigned to a depression group and compared to those who were free of depressive symptoms on behavioral and neuropsychological measures to determine if there were meaningful differences in cognition, behavior and motivation/self-perception between groups. METHOD: Adolescent girls were randomly selected from local schools to participate in a study of neuropsychological development in adolescence. Those who volunteered and whose parents reported them to be free of psychiatric disorders were enrolled and completed a battery of behavioral, neuropsychological and motivation/self-perception measures. RESULTS: The depressed group showed more behavioral problems, evaluated themselves as less competent, showed more extrinsic motivational orientation, had lower IQ and differed on a measure of visual spatial perception. CONCLUSION: The frequency of subclinical depression is high in adolescent girls, even when parents report no psychiatric/emotional problems. The increase in problem behaviors and extrinsic motivation, as well as the decrease in feelings of self-worth suggest that this group may benefit from intervention. Poorer performance on a measure of visual spatial perception needs further investigation to confirm its association with depression and understand its relationship to depressive symptoms.

Influence of depression on cognitive functioning in Fragile X females.

We sought to determine the frequency of a history of major depression in women with Fragile X syndrome. In addition, we attempted to disentangle the cognitive effects of major depression from those of Fragile X syndrome. Thirty-seven mothers of developmentally delayed children (Fragile X syndrome: n = 18; comparison group n = 19), matched for age, educational level, and socioeconomic status, were administered psychiatric and neuropsychological measures. Women with Fragile X syndrome had a higher frequency of lifetime diagnosis of major depressive disorder (78%) than the comparison group (37%). Mild impairment was seen on visuospatial construction and memory tasks in women with Fragile X syndrome, while women with depression showed subtle deficits in several aspects of visuospatial perception and learning. There was no interaction of Fragile X syndrome and depression in their influence on cognition. The results underscore the importance of considering the influence of depression on cognitive performance in studies of genetic disorders.

Relactation in a newborn intensive care setting.

A woman who did not initiate breastfeeding after the birth of her preterm infant did so 27 days later, after her infant developed necrotizing enterocolitis. Using specific strategies including kangaroo care principles and simultaneous breast pumping to facilitate relactation, the mother was able to provide an adequate supply of breastmilk at the time of her infant's hospital discharge.

Effects of nonnutritive sucking on behavioral organization and feeding performance in preterm infants.

The purpose of this study was to examine the effects of nonnutritive sucking (NNS) on behavioral organization and feeding performance in preterm infants. Thirteen preterm infants were observed at four bottle-feedings, two of which involved treatment with prefeeding NNS. NNS had a positive effect on oxygen saturation and behavior state, as well as on the initiation and duration of the first nutritive suck burst.

Behavioral adjustment of children with hydrocephalus: relationships with etiology, neurological, and family status.

Examined the relationship of hydrocephalus and behavioral adjustment in three groups of 5- to 7-year-old children (N = 84) with a history of early hydrocephalus (spina bifida, prematurity, aqueductal stenosis) and three non-hydrocephalic comparison groups (spina bifida, prematurity, normals). Results revealed no significant group differences on measures of behavioral adjustment and a variety of family and sociodemographic variables. Children with hydrocephalus were more likely to meet criteria for behavior problems, obtained lower scores on measures of adaptive behavior, and perceived themselves as less physically competent. Categorical modeling analyses showed that hydrocephalus and its treatment, gender, family variables, and motor skills were related to the presence of behavior problems.

Neurobehavioral characteristics of CGG amplification status in fragile X females.

Neurobehavioral correlates of CGG amplification were studied in 17 nonretarded adult female carriers of fragile X syndrome. The results revealed a significant relationship between IQ and the number of CGG repeats in the 5' untranslated region of the FMR1 gene. Women with a full mutation (> 200 CGG repeats) scored below average in IQ, visual-spatial perception, visual-spatial organization, and executive function. There were no differences in fine motor dexterity or memory as a function of CGG amplification status. A history of major depressive disorder was identified in 71% of the sample, but incidence of depression was not associated with the degree of CGG amplification. Schizotypal features were noted in 18%. No intellectual or neuropsychological deficit was found in women with a premutation (< 200 CGG repeats). Decrements in IQ, visual-spatial perception, and executive function appear to arise as a consequence of the CGG amplification.

Gunshot wounds to the brain in children and adolescents: age and neurobehavioral development.

Neurobehavioral outcome after craniocerebral gunshot wounds was evaluated in a prospective, 3-year, longitudinal follow-up of a consecutive case series of 13 children and adolescents. The younger group was composed of seven children, ages 1.5 to 4 years, and the older group contained six children, ages 5 to 14. Outcome measures included the Glasgow Outcome Scale and neuropsychological assessment of intelligence, language, motor, memory, attention, academic achievement, and adaptive behavior. Glasgow Outcome Scale scores at baseline indicated moderate and severe disabilities in 69 and 23%, respectively. At the 3-year follow-up, 85% had moderate disabilities but only 8% were severely disabled. Significant and persistent neurobehavioral deficits varied with developmental level at the time of cerebral insult. Intellectual functioning was clearly more impaired in children younger than 5 years of age at the time of injury than in older children. Cognitive and motor factors were most closely related to deficits in the younger group. Disability in older children and adolescents was associated with impaired attention, adaptive behavior, and behavioral disturbance. Disabilities appear to be at least as severe in our sample after cerebral gunshot wounds as in our studies of severe pediatric closed-head injury. At the time of follow-up, younger children sustaining gunshot wounds had slightly lower intelligence quotient scores and similar receptive language, expressive language, and gross motor scores compared with children with severe closed-head injury. The older gunshot wound patients were significantly more impaired than patients with severe closed-head injuries on measures of adaptive behavior and attention.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular effects of imipramine, fluvoxamine, and placebo in depressed outpatients.

BACKGROUND: The data presented represent cardiovascular parameters collected from one site of a larger, multicenter, double-blind, placebo-controlled, 6-week outpatient efficacy study of the serotonin uptake inhibitor fluvoxamine in depressed outpatients. METHOD: In this smaller study, we compared fluvoxamine (N = 17) to the prototypic antidepressant, imipramine (N = 14), and to placebo (N = 15). Specific parameters investigated were drug effects on postural pulse and blood pressure changes and ECG parameters including PR, QRS, and QTc intervals and ventricular heart rate. RESULTS: Fluvoxamine had few effects on measured parameters. Imipramine produced statistically significant changes on all measures; placebo had no effects on cardiac measures. CONCLUSION: Our data support that fluvoxamine, in a sample of healthy depressed outpatients, has little effect on cardiovascular function. Further study and clinical experience with this drug will be necessary before the full extent of its cardiac profile is known.

Cerebral white matter and cognition in hydrocephalic children.

Although children with hydrocephalus frequently show poor development of nonverbal cognitive skills relative to verbal skills, little is known about the neuropathologic correlates of these discrepancies. In this study, cerebral white-matter structures and lateral ventricles were measured from the magnetic resonance images of age-matched children with meningomyelocele, meningocele, and aqueductal stenosis and normal subjects. The volume of each lateral ventricle and the cross-sectional area of the corpus callosum and internal capsules were correlated with concurrent measures of verbal and nonverbal cognitive skills. The corpus callosum in the meningomyelocele and aqueductal stenosis groups was smaller. The lateral ventricles were larger, and the internal capsules were smaller, in all patient groups than in normal subjects. There were no differences in the size of the centra semiovale. Although verbal and nonverbal measures correlated positively with the size of the corpus callosum, the correlation was higher for nonverbal measures. Nonverbal measures correlated with the right, but not the left, lateral ventricle and with the area of the right and left internal capsules. Verbal measures correlated with the left, but not right, lateral ventricle and with the left, but not right, internal capsule. These results show a relationship between the corpus callosum and cognitive skills that is also influenced by hydrocephalus-related changes in the lateral ventricles and other cerebral white-matter tracts.

Verbal and nonverbal skill discrepancies in hydrocephalic children.

This study evaluated a large sample (N = 90) of 5- to 7-year-old children with hydrocephalus caused by aqueductal stenosis or prematurity-intraventricular hemorrhage or associated with spina bifida. Comparison groups of normal controls, children with spina bifida and no shunt, and premature children with no hydrocephalus were also evaluated. Comparison of skill discrepancies at two occasions separated by 1 year revealed that hydrocephalic children, as a group, showed poorer nonverbal than verbal skills on measures from the McCarthy Scales of Children's Abilities, the WISC-R, and composites of neuropsychological skills. No discrepancies in verbal-nonverbal memory were found nor were any discrepancies attributable to etiology or motor demands of the tasks. Consistent with current hypotheses concerning the role of the cerebral white matter in cognitive development, these results show that hydrocephalic children in this age range generally have poorer development of nonverbal cognitive skills relative to their language development.

Cognitive and motor skills in achondroplastic infants: neurologic and respiratory correlates.

Thirteen infants with achondroplasia underwent psychometric testing as part of a comprehensive neurologic assessment. As a group, mental development was average and motor development was delayed, although a wide range of scores was obtained. Foramen magnum measurements were correlated with respiratory dysfunction, abnormal somatosensory evoked potentials, and delayed motor development. Abnormal polysomnogram outcome was associated with reduced mental capacity. In light of the reported increased frequency of respiratory dysfunction in achondroplasia, these findings warrant careful attention and further study.

Left unilateral neglect in a preschool child.

The authors present a case of transient left hemispatial inattention following traumatic brain injury in a three-year-old child. Computed tomographic scan revealed a small right frontal and a right temporo-parietal contusion. Stimuli were developed to quantify the response difference between hemifields in this pre-literate child. Hemispatial inattention showed resolution at 19 days post-trauma and had completely resolved six months later. These findings suggest that right hemisphere systems subserve visually guided attention before six years of age.

Cognitive and motor abilities in preschool hydrocephalics.

The neuropsychological performance of three groups of preschool children was evaluated: (a) one with hydrocephalus associated with myelomeningocele; (b) one with hydrocephalus associated with intraventricular hemorrhage and very low birth weight; and (c) a nonhydrocephalic normal comparison group. Multivariate profile analysis revealed lower levels of performance on measures of verbal and nonverbal cognitive skills for both groups of hydrocephalic children relative to normals. Comparison of group profiles on tasks requiring figure copying as opposed to figure matching and analysis of specific gross and fine motor skills revealed that both hydrocephalic groups had impaired visual-motor integration in the presence of average visual perceptual matching. In addition, different patterns of motor skill deficits were found for each hydrocephalic group. The results of this study suggest that decreased visual-motor integration and etiology-specific motor deficits are major sequelae of these forms of hydrocephalus in the preschool years.

Analysis of change: modeling individual growth.

Research on change is complicated by problems of measurement and analysis stemming from a conceptualization of change as a series of accumulating increments and decrements. In contrast, individual growth curves depict change as a continuous process underlying individual performance. These two perspectives are reviewed, and some problems with the use of difference scores in the study of change are clarified. Traditional methods are contrasted with growth curve analysis for the purposes of measuring change and studying its correlates. An illustrative example of the use of growth curves is provided from research on recovery of cognitive function following pediatric closed head injury.